Development of materials, such as polymers, that can be utilized as implants or other devices that come in contact within the human body continues to be a major challenge. Although various polymers have found diversified biomedical applications, it is apparent that there is virtually no polymeric material available that does not require surface modifications to allow effective use thereof. By modifying polymer surfaces one may achieve a number of desirable properties ranging from blood clotting prevention to controllable drug release, and other applications, while maintaining useful bulk polymer properties.
A variety of polymers are being utilized in these and other biomedical applications; for example, polyvinyl chloride (PVC) is used in the manufacture of cardiac catheters, surgical tapes, artificial hearts, blood pumps and artificial limbs (Kroschwitz, 1989; Weber et al., 2003; Shalaby, 1994; Kim and Urban, 1998; DeHaan, 1971). In order to function properly in these devices, PVC requires specific surface modifications. Alternatively, polymethylmethacrylate (PMMA), which is utilized to produce contact lenses, bone cement, artificial teeth and dental fillings, requires different surface modifications in order to function properly (Pena et al., 1997; Andreopoulos et al., 1991; Frazer et al., 2005). Along the same lines, in order for polydimethylsiloxane (PDMS) to function properly as a component in contact lenses, artificial skin, oxygenators and certain drug delivery systems (Kroschwitz, 1989; Tokuyama et al., 2005; Schulze Nahrup et al, 2004; Niwa et al., 2001; Huck, 2005; Bae and Urban, 2004; Bae and Urban, 2006), it necessitates specific surface modifications that are different from those surface modifications required for the proper function of expanded polytetrafluoroethylene (ePTFE) in vascular graft prostheses, heart patches, and a stapes prosthesis (Kroschwitz, 1989; Swartbol et al., 1996; Renard et al., 1996; Kang et al., 1996; Jardine and Wilson, 2005; Dupuy et al., 2001; Catanese et al., 1999).
Regardless of specific surface modifications, all biomaterials are susceptible to bacterial colonization and growth, which can have detrimental effects on biomaterial. Thus, much effort has been made to generate polymeric surfaces with desirable bio-properties that exhibit antimicrobial activity. For example, a recent study by one of the inventors demonstrated that PDMS could be modified with amoxicillin, thereby rendering the PDMS surface as antimicrobial (Bae and Urban, 2006). Since ePTFE is a non-reactive and non-toxic fluoro-containing polymer, it has gained wide use in the medical field. For example, ePTFE can be incorporated in vascular grafts and mitral valve tendon replacements, and also finds application in orthopedic and reconstructive surgical practices (Rittgers et al., 1985; Mole, 1992; Bellon et al., 1993). However, when implanted into various biological environments, ePTFE performs similarly with other implanted polymeric materials insofar as bacterial colonization on the polymer surface is concerned (Johnell et al., 2005; Balazs et al., 2004); this problem remains a major obstacle to realizing the full potential of ePTFE polymer in biomedical and industrial applications.